U.S. patent application number 10/284512 was filed with the patent office on 2003-05-01 for return-to-port warning device and method.
Invention is credited to Motose, Hitoshi, Okuyama, Takashi.
Application Number | 20030082963 10/284512 |
Document ID | / |
Family ID | 19148511 |
Filed Date | 2003-05-01 |
United States Patent
Application |
20030082963 |
Kind Code |
A1 |
Motose, Hitoshi ; et
al. |
May 1, 2003 |
Return-to-port warning device and method
Abstract
A watercraft is equipped with an outboard motor and an inboard
local area network (LAN) that communicates control signals to the
outboard motor. An outboard motor operating device retains the
ability to operate the outboard motor even if part of the inboard
LAN develops an abnormality. In particular, a control signal that
controls the outboard motor and a conditional information signal
that indicates a condition of the watercraft are transmitted by
independent cables that are mutually separated. Even if the cable
for transmitting the conditional information signal or equipment
connected to the cable develops an abnormality, transmission of the
control signal for controlling the outboard motor is not hindered
since the control signal is on the other cable, which is not
affected by the abnormality. The conditional information signals
are processed to generate and display return-to-port warnings based
on the watercraft conditions and other operator issued
constraints.
Inventors: |
Motose, Hitoshi; (Hamamatsu,
JP) ; Okuyama, Takashi; (Hamamatsu, JP) |
Correspondence
Address: |
KNOBBE MARTENS OLSON & BEAR LLP
2040 MAIN STREET
FOURTEENTH FLOOR
IRVINE
CA
92614
US
|
Family ID: |
19148511 |
Appl. No.: |
10/284512 |
Filed: |
October 30, 2002 |
Current U.S.
Class: |
440/2 ;
440/3 |
Current CPC
Class: |
B63H 20/00 20130101;
F02B 61/045 20130101; B63H 21/22 20130101 |
Class at
Publication: |
440/2 ;
440/3 |
International
Class: |
B60L 001/14; B63H
021/20 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 30, 2001 |
JP |
2001-333207 |
Claims
What is claimed is:
1. An outboard motor comprising: a control input section that
receives at least one command to control an outboard motor; a
control section that controls the outboard motor in response to the
command received by the control input section; a conditional
information section that outputs at least one conditional
information signal indicative of a condition of a watercraft; a
first cable connected to the control input section; and a second
cable connected to the conditional information section, the second
cable separate from the first cable.
2. The outboard motor according to claim 1, wherein the command
received by the control input section includes at least one of a
throttling operation, a shifting operation, a steering operation, a
starting operation or a stopping operation of the outboard
motor.
3. The outboard motor according to claim 1, further comprising: an
indication device connected to the second cable; a display signal
transmitted by the second cable wherein the display signal includes
at least part of the information contained in the conditional
information signal.
4. The outboard motor according to claim 1, wherein the first and
second cables differ from each other by at least one of a size, a
shape or a color.
5. The outboard motor according to claim 1, wherein respective
first and second connector are connected to the first and second
cables, the first and second connectors having respective first and
second shapes, the first shape differing from the second shape.
6. An outboard motor operating device comprising: an indication
section that indicates a condition of a watercraft; a control input
section that receives at least one command to control the
watercraft and that outputs at least one control signal
corresponding to the command; a first cable that transmits the
control signal outputted from the control input section; and a
second cable that transmits a condition signal indicative of the
condition of the watercraft to the indication section, the second
cable separate from the first cable.
7. The outboard motor operating device according to claim 6,
further comprising a velocity calculation section that calculates a
velocity of the watercraft based on a change in location of the
watercraft with time, wherein the indication section indicates the
velocity calculated by the velocity calculation section.
8. The outboard motor operating device according to claim 6,
further comprising a fuel consumption ratio calculation section
that calculates a fuel consumption ratio of the watercraft based on
the velocity of the watercraft and based on a change in fuel
consumption by the outboard motor with time, wherein the indication
section indicates the fuel consumption ratio calculated by the fuel
consumption ratio calculation section.
9. The outboard motor operating device according to claim 6,
further comprising a residual amount of fuel calculation section
that calculates a residual amount of fuel of the watercraft based
on the fuel consumption of the outboard motor, wherein the
indication section indicates the residual amount of fuel calculated
by the residual amount-of-fuel calculation section.
10. The outboard motor operating device according to claim 6,
further comprising a maximum cruising distance calculation section
that calculates a maximum cruising distance of the watercraft based
on the fuel consumption ratio and the residual amount of fuel of
the watercraft, wherein the indication section indicates the
maximum cruising distance calculated by the maximum cruising
distance calculation section.
11. The outboard motor operating device according to claim 6,
further comprising a maximum cruising time calculation section that
calculates a maximum cruising time of the watercraft based on the
velocity and the maximum cruising distance of the watercraft,
wherein the indication section indicates the maximum cruising time
calculated by the maximum cruising time calculation section.
12. The outboard motor operating device according to claim 6,
further comprising a table that represents a relation between the
velocity of the watercraft and the optimum trim angle of the
outboard motor, wherein the indication section indicates an optimum
trim angle based on the table.
13. The outboard motor operating device according to claim 6,
wherein the indication section indicates a condition of the
outboard motor based on detection results by a detection section
that detects a condition of the outboard motor.
14. The outboard motor operating device according to claim 13,
wherein the watercraft comprises a plurality of outboard motors,
and the indication section also indicates conditions of the
plurality of outboard motors.
15. The outboard motor operating device according to claim 13,
further comprising a judgment section that determines whether the
condition of the outboard motor is within a normal range, wherein
when the judgment section determines that the condition of the
outboard motor is out of the normal range, the indication section
indicates information that the outboard motor is operating in an
abnormal region of the operating condition of the outboard
motor.
16. A watercraft comprising: an indication section that indicates a
condition of a watercraft; a control input section that receives at
least one command to control an outboard motor and that outputs a
control signal corresponding to the command; a first cable that
transmits the control signal outputted from the control input
section; a second cable that transmits a condition signal
indicative of the condition of the watercraft to the indication
section, the second cable separate from the first cable; a third
cable corresponding to the first cable, the third cable
transmitting the control signal; a fourth cable corresponding to
the second cable, the fourth cable transmitting the condition
signal, the fourth cable separate from the third cable; a control
section that controls the outboard motor based on the control
signal transmitted by the third cable; and a conditional
information section coupled to the control section via at least one
of the second cable and the fourth cable.
17. A return-to-port warning device comprising: a maximum cruising
distance calculation section that calculates a maximum cruising
distance based on a residual amount of fuel and a fuel consumption
ratio; a return-to-port distance calculation section that
calculates a return-to-port distance from the current location to a
home port; and a return-to-port judgment section that determines
whether a return-to-port warning is issued to indicate that the
watercraft should return to the home port in order to avoid fuel
exhaustion, the determination based on a comparison between the
maximum cruising distance calculated by the maximum cruising
distance calculation section and the return-to-port distance
calculated by the return-to-port distance calculation section.
18. The return-to-port warning device according to claim 17,
further comprising: an expected return-to-port time storage section
that stores an expected return-to-port time to the home port; an
arrival time calculation section that calculates an arrival time at
the home port based on the return-to-port distance calculated by
the return-to-port distance calculation section; and a second
return-to-port judgment section that determines whether a second
return-to-port warning is issued to indicate that the watercraft
should return to the home port in order to avoid arriving later
than the expected return-to-port time, the determination based on a
comparison between the arrival time calculated by the arrival time
calculation section and the expected return-to-port time.
19. A return-to-port warning method comprising: calculating a
maximum cruising distance based on a residual amount of fuel and a
fuel consumption ratio; calculating a return-to-port distance from
the current location to a home port; and determining whether to
issue a return-to-port warning to indicate that the watercraft
should return to the home port based on a comparison between the
calculated maximum cruising distance and the calculated
return-to-port distance.
20. The return-to-port warning method according to claim 19,
further comprising: calculating an arrival time at the home port
based on the calculated return-to-port distance; and determining
whether to issue a second return-to-port warning to indicate that
the watercraft should return to the home port based on a comparison
between the calculated arrival time and the expected return-to-port
time.
Description
PRIORITY INFORMATION
[0001] This application is based on and claims priority under 35
U.S.C. .sctn.119 to Japanese Patent Application No. 2001-333207
filed on Oct. 30, 2001, the entire contents of which are hereby
expressly incorporated by reference herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention is directed to a watercraft, and more
specifically, to a watercraft comprising an engine control unit
capable of producing a return-to port warning signal.
[0004] 2. Description of the Related Art
[0005] Watercraft such as pleasure boats, fishing boats, or the
like, use motors (e.g., outboard motors mounted on transoms) to
provide power to propellers or other thrust generating devices for
moving the watercraft forward and backward. For example, an
outboard motor typically incorporates an internal combustion engine
mounted at the top and external to the watercraft structure. The
motor is coupled to a propeller or other thrust generating device,
which is submerged in water and is used to propel the watercraft. A
typical outboard motor includes various linkages between the hull
and the motor that allow an operator control the operation of the
outboard motor. These linkages take various forms such as
mechanical cables, hydraulic lines, electrical wires, or fiber
optical cables.
[0006] For example, the outboard motor may include an air induction
system to provide air to the combustion chambers of the motor.
Frequently, the air induction system has a throttle valve to
regulate the quantity of air delivered to the engine's combustion
chambers in response to the operator. Alternatively, engine may
include a speed regulating device to control the speed of the
engine by controlling the amount of fuel delivered to the
combustion chambers or by controlling the ignition timing. In
either configuration, input from the operator is coupled to the
appropriate regulating mechanism of the motor located at the rear
of and externally to the hull of the watercraft. A controller
comprising a lever may be used that is pivotally or slidably
mounted to the body of the controller. As the operator moves the
lever the appropriate regulating mechanism controls operation of
the motor. Other components in the motor section of the watercraft
controlled by the operator require additional linkages between the
hull and motor. Such components include throttle actuators, shift
actuators, steering actuators, and trim control devices.
[0007] A watercraft may include a local area network (LAN) to
simplify the system of linkages between the hull and the motor. The
LAN may advantageously be coupled to sensors and other electronic
devices that monitor the states of the motor or other components
the watercraft. The LAN also communicates control signals from an
operator to the motor.
SUMMARY OF THE INVENTION
[0008] One potential problem with a local area network (LAN) that
interconnects components in a watercraft is that excessive noise in
a component connected to the network, the failure of such a
component, or the failure of network wiring can affect, sometimes
catastrophically, a critical part of the network, such as the
components and devices used to directly control the operation of an
outboard motor. For example, it is undesirable that the operation
and control of the outboard motor becomes difficult or impossible
because of an abnormality in the communication lines connected to a
fuel level detector or to a Global Positioning System (GPS)
receiver and processor (hereinafter GPS). Thus, a system for a
watercraft or an outboard motor or a combination of a watercraft
and an outboard motor with an inboard LAN is needed wherein the
outboard motor is controlled by a control device via a separate
portion of the LAN that is capable of retaining the operation
capabilities of the outboard motor even if another portion of the
inboard LAN develops an abnormality.
[0009] One aspect of an embodiment in accordance with the present
invention is a control system for an outboard motor that comprises
a control input section, a control section, and a conditional
information section. The control input section receives at least
one command to control an outboard motor. The control section
controls the outboard motor in response to the command received by
the control input section. The conditional information section
outputs at least one conditional information signal indicative of a
condition of a watercraft. The outboard motor further comprises a
first cable is connected to the control input section and a second
cable connected to the conditional information section, where the
second cable separate from the first cable.
[0010] The control input section produces a control signal via the
first cable that is used to control the outboard motor. Thus, the
conditional information signal is differentiated from the control
signal that controls and operation of the outboard motor.
Therefore, even if the second cable for transmitting the
conditional information signal or equipment connected to the second
cable develops an abnormality, the transmission of the control
signal in the first cable for controlling the outboard motor is not
hindered.
[0011] The control signal outputted by the control input section
may include a signal that is used by the controls the performance
of one or more of a throttling operation, a shifting operation, a
steering operation of the outboard motor, starting the engine or
stopping the engine. For example, the control signals are
advantageously used to control a throttle actuator for operating a
throttle connected to the outboard motor, or the like.
[0012] The outboard motor may also advantageously include an
indication device such as a display device (e.g., video monitor)
that receives a signal that indicates the conditional information
of the watercraft. The displayed information may represent raw data
as sent by, for example, a sensor, or the displayed information may
represent processed data derived from calculations based, at least
in part, on such raw data. The signal received by the indication
device is used to indicate at least one condition of the watercraft
to a driver, but this signal is not use to control the outboard
motor.
[0013] The first and second cables may be different from each other
in colors, shapes, or diameters. By using different colors, shapes,
and diameters of the cables, the cables transmitting the control
signal and the cables transmitting the conditional information
signal are easier to discriminate, thus reducing or preventing
misconnection of the cables. For example, if the cables for each
type of signal includes multiple interconnected cables, the cables
corresponding to each type of signal advantageously have
corresponding colors or diameters (for example, the same color or
diameter) so that only the cables communicating the same types of
signals are interconnected.
[0014] In particularly preferred embodiments, the cables have
connectors, and the connectors for the cable for the control
signals are different from the connectors for the cables for the
conditional information signals. The different connectors prevent
incorrect coupling of a cable for the control signals with a cable
for the conditional information signals.
[0015] Another aspect in accordance with embodiments of the present
invention is an outboard motor operating device. The outboard
operating device comprises an indication section and a control
input section. The indication section indicates a condition of a
watercraft, while the control input section receives at least one
command to control the watercraft and outputs at least one control
signal corresponding to the command. The outboard operating device
further comprises a first cable that transmits the control signal
outputted from the control input section and a second cable that
transmits a condition signal indicative of the condition of the
watercraft to the indication section, where the second cable
separate from the first cable.
[0016] The control signal and the condition signal are transmitted
by separate cables. Therefore, even if the cable for transmitting
the condition signal or equipment connected to the cable develops
an abnormality, the transmission of the control signal for
controlling the outboard motor is not hindered.
[0017] In accordance with another aspect of embodiments of present
invention, a watercraft comprises an indication section and a
control input section. The indication section indicates a condition
of a watercraft, while the control input section receives at least
one command to control an outboard motor and outputs a control
signal corresponding to the command. The watercraft further
comprises a first cable that transmits the control signal outputted
from the control input section and a second cable that transmits a
condition signal indicative of the condition of the watercraft to
the indication section, wherein the second cable is separate from
the first cable. The watercraft further comprises a third cable
corresponding to the first cable that transmits the control signal
and a fourth cable corresponding to the second cable that transmits
the condition signal, wherein the fourth cable is separate from the
third cable. The watercraft further comprises a control section
that controls the outboard motor based on the control signal
transmitted by the third cable and a conditional information
section coupled to the control section via at least one of the
second cable and the fourth cable.
[0018] Cables for transmitting a control signal between the
outboard motor and the hull are provided separately for the control
signal and the conditional information signals, so that even if a
cable for transmitting the condition signal develops an abnormality
or even if equipment connected to the cable develops an
abnormality, transmission of the control signal for controlling the
outboard motor on the separate cable is not hindered.
[0019] During operation of a watercraft, a course is plotted that
typically involves meeting certain fuel constraints, time
constraints or a combination of fuel constraints and time
constraints. Meeting such constraints involves monitoring the
distance to a destination, the amount of fuel remaining in the fuel
tank, and the current time. A Global Positioning System (GPS) may
be used to enable the operator to determine the distance to the
destination by providing the current coordinates of the watercraft
and by comparing these coordinates to known destination
coordinates. This information, combined with a measure of the fuel
remaining in the fuel tank, allows the operator to determine, for
example, the distance of watercraft from the destination, whether
the watercraft has sufficient fuel to reach the destination, and
the amount of time required to arrive at the destination at an
expected watercraft velocity. However, an operator typically is
more concerned with the other aspects of a watercraft activity,
such as fishing, water-skiing, or the like. Thus, a need exists for
an automated system for informing an operator that a potential
problem exists with respect to an available quantity of fuel or an
available amount time to return to a home port. As discussed below,
one aspect of embodiments in accordance with the present invention
is a system that automates the calculation of the trip constraints,
such as the constraints discussed above, and that warns an operator
when a potential problem exists.
[0020] Another aspect in accordance with embodiments of the present
invention is a return-to-port warning device. The return-to-port
warning device comprises a maximum cruising distance calculation
section that calculates a maximum cruising distance based on a
residual amount of fuel and a fuel consumption ratio. A
return-to-port distance calculation section calculates a
return-to-port distance from the current location to a home port. A
return-to-port judgment section judges whether a return-to-port
warning is issued to encourage the operator of the watercraft to
return to the home port. The return-to-port judgment section bases
a judgment on a comparison between the maximum cruising distance
calculated by the maximum cruising distance calculation section and
the return-to-port distance calculated by the return-to-port
distance calculation section. The maximum cruising distance
calculated from the residual amount of fuel is compared with a
distance to the home port, and a return-to-port warning is issued
when the maximum cruising distance approaches the distance to the
home port. By providing the return-to-port warning, situations are
prevented in which a watercraft operator fails to notice that the
residual fuel has become too low or that the watercraft is too far
away from the home port such that returning to the home port
becomes difficult or impossible because of insufficient fuel.
[0021] In embodiments in accordance with this aspect, the
return-to-port warning device comprises an expected return-to-port
time storage section that stores an expected return-to-port time
(e.g., a time by which the operator planned to return to the home
port or other port of the watercraft). An arrival time calculation
section calculates an estimated arrival time at the home port based
on the return-to-port distance calculated by the return-to-port
distance calculation section and a watercraft velocity. A second
return-to-port judgment section judges whether a second
return-to-port warning is issued to encourage the operator of the
watercraft to return to the home port. The second judgment section
judges whether to issue the second return-to-port warning based on
a comparison between the arrival time calculated by the arrival
time calculation section and the expected return-to-port time
stored in the expected return-to-port time storage section. This
aspect of the preferred embodiments prevents a situation in which
time has elapsed without being noticed by the watercraft operator
or a situation in which the watercraft has cruised too far away
from the home port such that that an insufficient time remains for
the watercraft to return to the home port by the expected
return-to-port time.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Preferred embodiments in accordance with aspects of the
present invention will be described below in connection with the
accompanying drawing figures in which:
[0023] FIG. 1 is a perspective view showing a watercraft according
to an embodiment of the present invention;.
[0024] FIG. 2 is a block diagram showing the general construction
of a watercraft according to an embodiment of this invention;
and
[0025] FIG. 3 is a flowchart showing a procedure for a
return-to-port consistent with embodiments of the present
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0026] FIGS. 1-3 illustrate the overall construction and operation
of a watercraft 10 that employs a LAN in accordance with certain
features, aspects, and advantages of the present invention. The use
of a LAN in conjunction with an outboard motor, as shown in FIGS.
1-3, is illustrative of a typical application of the present
invention and should not be construed as limiting. For instance,
certain features, aspects, and advantages of the present invention
find application in a wide variety of watercraft.
[0027] FIG. 1 illustrates a perspective view of the watercraft 10
in accordance with a preferred embodiment of the present invention.
As shown in FIG. 2, the watercraft 10 comprises a hull 11 and an
outboard motor 12 mounted to the hull 11. The watercraft 10 further
includes a first connecting line 13 and a second connecting line 14
that interconnect electronic circuits on the hull 11 and electronic
circuits on the outboard motor 12. In certain embodiments, the hull
11 comprises a control unit 20 that enables an operator to control
the operations of the outboard motor 12 from a pilot or operator's
seat in a cockpit area of the hull. For example, as shown in FIG.
2, the control unit 20 includes a start/stop switch 21, a lever
angle sensor 22 and a trim/tilt switch 23. The control unit 20
further includes a steering device 30 connected to a steering
sensor 31. The hull 11 further comprises an inboard indication
device 41; a Global Positioning System (GPS) 42; a fuel level
detector 51; a fuel flow detector 52; and a fuel tank 53.
[0028] In particular embodiments, the outboard motor 12 comprises
an engine control unit (ECU) 61, an engine 62, a transmission 63,
and a thrust generator (e.g., a propeller) 64. The ECU 61 is
connected to a plurality of sensors such as, for example, a
throttle opening sensor 71, a shift position sensor 72, an motor
angle sensor 73, and an engine speed sensor (e.g., a tachometer)
74. The ECU 61 is also connected to a plurality of actuators such
as, for example, a throttle actuator 81, a shift actuator 82, a
steering actuator 83, and a trim control device 84.
[0029] The ECU 61 controls the general operations of the outboard
motor 12 and advantageously comprises a central processing unit
(CPU), one or more storage devices (e.g., RAM, ROM, EPROM, etc.),
one or more auxiliary storage devices (e.g., non-volatile RAM, hard
disc, CD-ROM, optical or magnetic disc, etc.), and a clock.
[0030] The connecting line 13 comprises a cable 131 that originates
in the hull 11 and a cable 134 that originates in the outboard
motor 12. A connector 132 is coupled to a free end of the cable
131, and a connector 133 is coupled to a free end of the cable 134.
The connector 132 is normally connected to the connector 133 to
thereby interconnect the cable 131 and the cable 134 as the
connecting line 13.
[0031] The connecting line 14 comprises a cable 141 that originates
in the hull 11 and a cable 144 that originates in the outboard
motor 12. A connector 142 is coupled to a free end of the cable
141, and a connector 143 is coupled to a free end of the cable 144.
The connector 142 is normally connected to the connector 143 to
thereby interconnect the cable 141 and the cable 144 as the
connecting line 14.
[0032] The start/stop switch 21 is a switching device that produces
a start/stop signal that the operator activates in a first manner
to start the engine 62 and that the operator activates in a second
manner to stop the engine 62. For example, in particular
embodiments, the start/stop switch 21 produces a first logic signal
to start the engine 62 and produces a second logic signal to stop
the engine 62. Alternatively, the start/stop switch 21 may comprise
two switching elements, with one switching element generating a
start signal and the other switching element producing a stop
signal.
[0033] In particular embodiments, the lever angle sensor 22 detects
the inclination (angle) of a remote control lever 85 of the remote
control 20. The ECU 61 uses the lever angle signal from the lever
angle sensor 22 to adjust the throttle actuator 81 and to adjust
the shift actuator 82. For example, the ECU 61 is advantageously
programmed such that when the remote control lever 85 is in a
neutral position, no power is communicated to the propeller 64, and
the propeller 64 does not rotate. Thus, no thrust is applied to the
watercraft 10 when the remote control lever 85 is in the neutral
position.
[0034] The ECU 61 is advantageously further programmed such that
when the remote control lever 85 is inclined toward the bow from
the neutral position, power is communicated to the propeller 64 via
the transmission 63 to cause the propeller 64 to rotate in a first
rotational direction to cause the watercraft 10 move in a forward
direction (e.g., in the general direction in which the bow of the
hull is pointing). Conversely, when the remote control lever 85 is
inclined toward the stem from the neutral position, power is
communicated to the propeller 64 via the transmission 63 to cause
the propeller 64 to rotate in a second rotational direction
opposite the first rotational direction to cause the watercraft 10
to move in a backward direction opposite the forward direction.
[0035] The ECU 61 is advantageously further programmed such that
when the remote control lever 85 is inclined toward the bow or the
stem by more than a threshold angle, the throttle of the engine 62
is operated gradually to increase the rotational speed of the
propeller 64 to increase the watercraft velocity. Other embodiments
of the remote control lever 85 and lever angle sensor 22 are
consistent with the present invention. For instance, remote control
lever 85 may comprise separate levers for the shift control
function and the throttle control function. The remote control
lever 85 may also take the form of a computer input device such as
a key board, mouse, or similar device. In such embodiments, the
remote control lever 85 interfaces directly with the ECU 61 without
needing the lever angle sensor 22. In other embodiments, the remote
control lever 85 interfaces with a separate, microprocessor-driven
device that communicates with the ECU 61 via the connecting line
13.
[0036] The trim/tilt switch 23 preferably comprises a switching
device that produces a trim/tilt control signal to control the trim
control device 84. The trim control device 84 is controls an
actuator (not shown) that adjusts the tilt and trim of the outboard
motor 12. As described in greater detail below, the pitch (e.g.,
the up or down position) of the bow 11 of the watercraft 10 during
operation is controlled in response to the operator setting the
trim/tilt switch 23 upwardly and downwardly. Controlling the pitch
of the bow enables the operator to select a condition that effects
a balance between efficiency (in terms of rate of fuel consumption)
and stability of watercraft during maneuvering.
[0037] The steering device 30 preferably comprises a steering
wheel, and the steering sensor 31 detects the angular orientation
of the steering device 30 with respect to a neutral position of the
steering device 30. The steering sensor 31 outputs a steering angle
control signal to the ECU 61. The ECU 61 is responsive to the
steering angle control signal to control the steering actuator 83
in the outboard motor 12. When the operator turns the steering
device 30, the steering actuator 83 changes the angular orientation
in a horizontal plane of the outboard motor 12 relative to the hull
11, which changes the direction in which the thrust generated by
the propeller 64 is applied with respect to the hull 11. Thus, the
direction of motion of the watercraft 10 through the water is
controlled in response to the steering commands of the operator
applied to the steering device 30.
[0038] The indication device 41 preferably comprises a display
device such as, for example, a CRT (cathode-ray tube) or an LCD
(liquid crystal display). The indication device 41 provides the
operator with a plurality of types of information described below.
For example, the types of displayed information may include
information representing the state (e.g., operating conditions) of
the watercraft 10.
[0039] The GPS 42 advantageously determines the current location of
the watercraft 10 based on a signals transmitted from a plurality
of satellites. In particular, the GPS 42 processes the signals
received from the satellites to calculate the current coordinates
of the watercraft 10. The GPS 42 outputs the coordinate information
in an appropriate format to the ECU 61 via the cable 31.
[0040] The fuel level detector 51 detects the amount of fuel
remaining in the fuel tank 53, which amount decreases as the fuel
tank 53 supplies fuel to the engine 62. The fuel level detector 51
outputs a signal representing the amount of fuel remaining in the
fuel tank 53 to the ECU 61 via the cable 31 in an appropriate
format.
[0041] The fuel flow detector 52 detects the rate of flow rate of
fuel from the fuel tank 53 to the engine 62 in units of volume per
unit time (e.g., gallons per hour or liters per minute). The fuel
flow information is advantageously combined with the fuel level
information from the fuel level detector 51 to enable the ECU 61 to
calculate a maximum cruising time. In particular embodiments, the
velocity of the watercraft 61 is also known, and the velocity
information is combined with the maximum cruising time to calculate
a maximum cruising distance.
[0042] In certain embodiments, the ECU 61 functions as a control
section that controls the watercraft 10 in response to one or more
commands received by a control input section. The control input
section receives operational information (e.g., manual inputs
applied by the watercraft operator) that is used to operate an
outboard motor 12 and outputs at least one control signal in
response to the operational information. Preferably, the control
input section comprises the steering sensor 31 and the various
devices of the control unit 20 (e.g., the start/stop switch 21, the
lever angle sensor 22, and the trim/tilt switch 23); however, as
will be appreciated by one skilled in the art, the control input
section may additionally comprise other devices. For instance, the
remote control lever 85 may have separate levers for the shift
control function and the throttle control function. In such a case,
the control input section would comprise an additional lever angle
sensor similar to the lever angle sensor 22.
[0043] In certain embodiments, the control section (i.e., the ECU
61) also receives information indicative of the condition of the
watercraft 10 from a conditional information section that outputs
at least one conditional information signal. Preferably, the
conditional information section comprises the GPS 42, the fuel
level detector 51, and fuel flow detector 52, although other
combinations of more or fewer components are also consistent with
embodiments of the present invention. The output from conditional
information section is indicative of the condition of the
watercraft 10. In certain embodiments, the control section sends a
condition signal to an indication section, such as the screen of
the indication device 41, based on the information contained in the
conditional information signal. Preferably, as discussed in more
detail below herein, the ECU 61 uses information from the
conditional information section to make further calculations
regarding the state of the watercraft 10 that are also displayed on
the indication device 41 or other output device.
[0044] As discussed above, the engine 62 is coupled to the
propeller 64 via the transmission 63 to provide the propulsion
force that moves the watercraft 10 through the water. The engine 62
is started from a stopping condition or stopped from an operating
condition, based on a start/stop signal from the start/stop switch
21. Preferably, the engine has a throttle (not shown) for
controlling the amount of fuel and air supplied to the combustion
chamber and thereby controlling engine speed. Other devices for
controlling engine speed may also be used.
[0045] The transmission 63 comprises a shifter (not shown) that
adjusts the torque range produced at the propeller 64 by the engine
62. The shifter also enables the propeller 64 to be in a neutral
condition of no rotation, a condition of normal rotation and a
condition of reverse rotation. The neutral condition may be used
when idling and as an intermediate condition between the condition
of normal rotation and the condition of reverse rotation. Thus, the
power applied to the propeller 64 is advantageously removed before
changing the direction of rotation of the propeller 64.
[0046] The throttle opening sensor 71 detects a degree of opening
of the throttle of the engine 62 and outputs this information to
the ECU 61. The shift position sensor 72 detects the position
(e.g., neutral, advance, and reverse) of the shifter of the
transmission 63 and outputs this information to the ECU 61. The
motor angle sensor 73 detects the angular orientation of the
outboard motor 12 relative to the hull 11 about an axis
substantially normal to a horizontal plane (e.g., the steering
angle of the outboard motor 12) and outputs this information to the
ECU 61. The engine speed sensor 74 detects the rotational speed of
the engine 62 in units of revolution per unit time and outputs this
information to the ECU 61.
[0047] The throttle actuator 81 is responsive to control signals
from the ECU 61 and controls the amount of opening of the throttle
of the engine 62. In preferred embodiments, the output of the
throttle actuator 81 is based on the lever angle signal from the
lever angle sensor 22 via the ECU 61. For example, as discussed
above, the speed of the engine 62 is advantageously changed in
response to the inclination angle (relative to the neutral
position) of the remote control lever 85.
[0048] The shift actuator 82 is responsive to control signals from
the ECU 61 and controls the operation of the shifter of the
transmission 63. Preferably, the output of the shift actuator 82 is
based on the lever angle signal from the lever angle sensor 22. For
example, as discussed above the propeller 64 is advantageously
caused to rotate in the forward direction when the remote control
lever 85 is inclined toward the bow and is advantageously caused to
rotate in the reverse direction when the remote control lever 85 is
inclined toward the stem. When the remote control lever 85 is in a
neutral position between the two inclined positions, the propeller
64 advantageously does not rotate.
[0049] The steering actuator 83 changes the orientation of the
outboard motor 12 with respect to the hull 11 to effect directional
control of the watercraft 10. Preferably, the output of the
steering actuator 83 is responsive to the steering angle signal
from the steering sensor 31, which is processed by the ECU 61 to
produce a control signal to the actuator 83. For example, when the
operator turns the steering device 30, direction of thrust of the
propeller 64 is changes to change the direction of movement of the
watercraft 10.
[0050] The trim control device 84 controls the tilt (trim angle) of
the outboard motor 12 based on input from the trim/tilt switch 23,
which is processed by the ECU 61 to produce the control signals
applied to the trim control device. In particular embodiments, when
the operator moves the trim/tilt switch 23 upward to increase the
tilt of the outboard motor 12 towards the tilting area, the bow of
the watercraft 10 raises as the watercraft 10 moves through the
water. Conversely, when the operator moves the trim/tilt switch 23
downward to decrease the tilt of the outboard motor 12 toward the
trimming area, the bow of the watercraft 10 lowers as the
watercraft 10 moves through the water.
[0051] As set forth above, the trim control device 84 controls the
position of the bow of the watercraft 10 in the water in response
to the operators activation of the tilt/trim switch 23. An
excessive rise of the bow results in a drop in performance in terms
of rate of fuel consumption because of the increased water
resistance at the hull bottom. Conversely, when the bow is too low,
acceleration from a stopped condition is improved, but the
stability of the watercraft 10 decreases. The watercraft 10 may
also experience difficulties during maneuvering because of the
increased water resistance at the bow when running at high speeds.
In general both the fuel efficiency and stability are affected when
the angle between the keel line and the water surface is changes by
just a few degrees.
[0052] The amount of the bow that is in the water depends on the
trim angle and also depends on the velocity of the watercraft, the
load weight (number of passengers and crew members), and other
conditions of the watercraft 10. Therefore, a low rate of fuel
consumption and stability can be maintained by properly selecting
the trim angle for a given set of conditions (e.g., velocity, load
weight, and other relevant conditions).
[0053] FIG. 2 illustrates additional details regarding the link
between the ECU 61 and the various components located in the hull
11. In particular embodiments, the link between the ECU 61 and the
components in the hull 11 comprises the connecting lines 13 and 14.
The connecting line 13 comprises the cable 131, the connectors 132,
133, and the cable 134. The cable 131 is connected to the
start/stop switch 21, to the lever angle sensor 22, to the
trim/tilt switch 23, and to the steering sensor 31. The connecting
line 13 transmits the control signals produced by these components
to the ECU 61, where the control signals are used by the ECU 61 to
generate signals to control the outboard motor 12.
[0054] The connecting line 14 comprises the cable 141, the
connectors 142, 143, and the cable 144. In particular embodiments,
the cable 141 is connected to the indication device 41, to the GPS
42, to the fuel level detector 51, and to the fuel flow detector
52. The connecting line 14 transmits positioning information from
the GPS 42, fuel level information from the fuel level detector 51,
and fuel flow information from the fuel flow detector 52 to the ECU
61. Preferably, the ECU 61 uses this information as a basis for
performing a plurality of calculations, described below, to
generate additional information regarding the operation of the
watercraft 10. The ECU 61 transmits the information from the GPS
42, the fuel level detector 51, the fuel flow detector 52, and the
resulting calculations to the indication device 41 via the cable
14.
[0055] As can be seen from the foregoing, the connecting line 13
(cables 131, 134) is a transmission path for control signals and
forms part of a control system used to control the outboard motor
12. In contrast, the connecting line 14 (cables 141, 144) is a
transmission path for information and forms part of an information
system that provides information to the operator regarding the
state of the watercraft. Thus, the connecting line 14 is not used
to transmit signals to control the outboard motor 12. The
connecting line 13 is vital to the operation of the watercraft 10.
In particular embodiments, the connecting line 14 is less critical
to the operation of the watercraft 10. By maintaining this
distinction between the connecting lines 13, 14, the cables of the
two connecting lines 13, 14 are physically separated to thereby
physically separate the connecting lines for the control system
from the connecting lines for the information system. Physically
separating the information lines from the control lines offers at
least two advantages described below.
[0056] The use of separate connecting lines 13, 14 mitigates the
possibility of mutual interference between the control system and
the information system. Specifically, if the wiring of the
information system (e.g., the connecting line 14) or equipment
connected to corresponding connection nodes (e.g., I/O equipment
such as the indication device 41 or the GPS 42) develop any
abnormalities, any resulting abnormal condition does not affect the
control system (e.g., the connecting line 13) or any of the
equipment connected to corresponding connection nodes (e.g., I/O
equipment such as the start/stop switch 21). For example, even if
the connecting line 14 is cut or short-circuited, the operator of
the watercraft 10 continues to maintain control of the outboard
motor 12 via the connecting line 13.
[0057] Another advantage of physically separating the cables of the
connecting line 13 from the cables of the connecting line 14 is a
reduction in the possibility of wiring errors. An outboard motor is
generally mounted onto the hull 11 by a builder of the hull or by
the boat dealer. Generally, the manufacturer of the outboard motor
supplies the outboard motor to the boat builder or boat dealer as
an independent unit. Therefore, unlike the personnel who
manufacture the outboard motor, the personnel mounting the outboard
motor to the hull and assembling the cables 13, 14 may not possess
a high level of technical skill. When a single cable contains a
plurality of types wires, a possibility exists for the mounting and
assembling personnel to make mistakes when interconnecting the
individual wires from the outboard motor to the individual wires
from the hull. By using separate cables for the information system
and the control system, the possibility of a misconnection by a
workman is decreased. Consistent with preferred embodiments of the
present invention, the possibility of an incorrect interconnection
of a one of the cables of the line 13 to one of the cables of the
line 14 is decreased by conforming to the measures described
below.
[0058] Preferably, a different type of connector is used for the
connectors 132, 133 than is used for the connectors 142, 143. As a
result, misconnection of the connector 132 to the connector 143 or
misconnection of the connector 133 to the connector 142 is
prevented. A wiring error caused by misconnection between the
non-matching connectors is precluded since the non-matching
connectors are not engageable to each other. In particular
embodiments, the diameters of the connectors 132, 133 are
preferably limited to not more than about 40 millimeters because of
handling considerations in the hull 11. Since the wiring of the
cables 131, 141 on the hull 11 side are typically laid through a
pipe (inboard piping), the wiring of the cables 131, 141 becomes
difficult unless connectors (e.g., the connectors 132 and 142) are
used that have outside diameters that are smaller than the inside
diameter of this inboard piping.
[0059] Preferably, different insulator colors are used on the wires
of the cables 131, 134 than are used on the cables 141, 144. Wiring
errors caused by misconnection of the cables 131, 134 or the like
can be prevented if the colors of the cables 131 and 141 and the
colors of the cables 134 and 144 are checked while performing the
connecting work during installation of the motor on the hull. In
particular embodiments, the wire insulators of the cables 131, 134
have the same color (e.g., red). Likewise, the wire insulators of
the cables 141, 144 have the same color (e.g., white) that is
different from the color of the cables 131, 134. In other
embodiments, other markings, such as stripes, may be further used
to distinguish the cables 131, 134 from the cables 141, 144 These
examples are not to be construed as limiting, since other
combinations of creating two sets of wire insulators that are
distinct from one another are consistent with embodiments of the
present invention.
[0060] Alternatively or in addition to the foregoing, wires with
different thicknesses may also be used to create the two sets of
cables such that the cables 131, 134 and the cables 141, 144 are
distinct from one another. For example, wiring errors by
misconnection of the cables 131 to the cable 144 or the like can be
prevented if the thicknesses of the cable 131 and the cable 144 are
checked while performing the connecting operation. In a particular
example, the cable 131 and the cable 134 have a same first diameter
that is different from a second diameter of the cable 141 and the
cable 144.
[0061] In particular embodiments, such as the embodiment
schematically illustrated in FIG. 2, the ECU 61 receives signals
and information from a plurality of sensors, detectors, switches,
and instruments located throughout the watercraft 10, and, in
particular, located inside the outboard motor 12. During operation
of the watercraft 10, information signals representing the states
of the watercraft 10 and the outboard motor 12 are sent by the ECU
61 to the indication device 41 to cause information to be displayed
in a manner discernible to the watercraft operator. This
information comprises, for example, first data from various
sensors, detectors, switches, and instruments located in the
watercraft 10, and second data representing the results of
calculations performed by the ECU 61 based on the first data.
[0062] Preferably, the ECU 61 transmits information to the
indication section (e.g., the screen of the indication device 41)
as well as to any other output devices that may advantageously be
used to inform or warn the operator regarding the state of the
watercraft 10 or other monitored condition. In particularly
preferred embodiments, the information transmitted to and displayed
on the display 41 includes, for example, a velocity S of the
watercraft 10, a fuel consumption ratio E of the watercraft 10, an
amount of remaining fuel .DELTA.V in the fuel tank 53, a maximum
cruising distance L based in part on the remaining fuel in the fuel
tank, a maximum cruising time T based in part on the remaining fuel
in the fuel tank, a return-to-port warning indication when one or
more of the conditions of the watercraft is approaching or has
reached an abnormal condition, an optimum trim position (angle) for
the outboard motor, and other conditions and parameters of the
watercraft 10 and the engine 62.
[0063] The foregoing items of information displayed in the
indication section are exemplary, and it should be understood that
other information and warnings consistent with embodiments of the
present invention may be transmitted by the ECU 61 to a suitable
indication device to inform or warn the operator regarding other
states of the watercraft 10 and the outboard motor 12. Additional
detail regarding the calculation of the foregoing information is
provided in the following paragraphs.
[0064] Velocity S
[0065] The GPS 42 provides coordinates defining the current
position of the watercraft 10. Preferably, the ECU 61 includes a
velocity calculation section that calculates a value for the
distance .DELTA.L traveled by the watercraft 10 over a period of
time .DELTA.t by obtaining coordinates of the watercraft 10 from
the GPS 42 at two or more different times separated by .DELTA.t.
The velocity calculation section estimates the velocity S of the
watercraft 10 is estimated by dividing the distance .DELTA.L by the
corresponding time interval .DELTA.t in accordance with the
following equation:
S=.DELTA.L/.DELTA.t. (1)
[0066] In the foregoing expression, the velocity S advantageously
is expressed in units of kilometers per hour (km/h) or knots
(nautical miles per hour).
[0067] Fuel Consumption Ratio E
[0068] The fuel flow detector 52 produces a signal indicates the
rate of fuel consumption F in units of volume or mass per unit time
(e.g., liters/hour). Preferably, the ECU 61 includes a consumption
ratio calculation section that calculates a fuel consumption ratio
E in units of volume or mass per unit distance (e.g.,
liters/kilometer or liters/nautical mile) based on the rate of fuel
consumption F and the calculated velocity S of the watercraft 10 in
accordance with the following equation:
E=F/S. (2)
[0069] The rate of fuel consumption F usually depends on the
velocity S. Therefore, the fuel consumption ratio E also usually
depends on the velocity S. The fuel consumption ratio E generally
decreases with increasing velocity S.
[0070] Amount of Remaining Fuel .DELTA.V in the Fuel Tank
[0071] Preferably, the ECU 61 receives a signal from the fuel level
detector 51 that indicates the amount of remaining fuel .DELTA.V in
the fuel tank 53 in units of volume or mass (e.g., liters). In
other embodiments, the amount of remaining fuel .DELTA.V is
calculated by the ECU 61 based on the signal produced by the fuel
flow detector 52 based on the following equation:
.DELTA.V=V0-V1, (3)
[0072] where V0 is the initial amount of fuel contained by the fuel
tank 53 and V1 is the amount of fuel consumed by the engine 62.
Preferably, the ECU 61 includes residual amount of fuel calculation
section that estimates the amount of fuel consumed, V1, based on
integration of the signal from fuel flow detector 52 over time.
[0073] Maximum Cruising Distance L
[0074] Preferably, the ECU 61 includes maximum cruising distance
calculation section that produces an estimate of the maximum
cruising distance L, which is the maximum distance the watercraft
10 can travel from the current location of the watercraft 10 based
on the amount of remaining fuel .DELTA.V and the current fuel
consumption ratio E. The maximum cruising distance L is determined
by the in accordance with the following equation:
L=.DELTA.V.times.E. (4)
[0075] The maximum cruising distance L calculated using the
foregoing relationship depends on the velocity S because the fuel
consumption ratio E changes with the watercraft velocity S. That
is, the maximum cruising distance L obtainable by the watercraft 10
depends on the current watercraft velocity S and may change if the
watercraft velocity S is changed.
[0076] Maximum Cruising Time T
[0077] Preferably, the ECU 61 includes maximum cruising time
calculation section that produces an estimate of the maximum
cruising time T, which is a length of time that the watercraft 10
can continue to travel at the current velocity S. The maximum
cruising time T is calculated by the ECU 61 using the maximum
cruising distance L and the watercraft velocity S by using the
following equation:
T=L/S. (5)
[0078] Return-To-Port Warning
[0079] In a preferred embodiment, a return-to-port warning device
determines when conditions are such that the watercraft operator
should set a course back to the home port and issues a
return-to-port warning to one or more output devices such as the
indication device 41. Preferably, the ECU 61 includes
return-to-port warning section that generates the return-to-port
warning when the ECU 61 determines that certain conditions of the
watercraft 10 or the motor 12 are true. The return-to-port warning
advises the operator that conditions are such that the operators
should apply control inputs to the watercraft 10 to initiate a
course back to the home port (or other designated location)
programmed into the ECU 61. The home port may be a port where the
watercraft initially started or the home port may be a destination
port.
[0080] The return-to-port warnings issued by the ECU 61 include at
least two different warnings that are issued under differing
conditions. A return-to-port distance calculation section and a
first return-to-port judgement section are used to produce
return-to-port distance warning when the maximum cruising distance
L approaches the distance of the watercraft 10 from the home
port.
[0081] The return-to-port distance calculation section and a second
return-to-port judgement section are used to produce return-to-port
time warning when the expected arrival time at the home port, based
on a velocity of the watercraft 10 and the distance of the
watercraft 10 from the home port, is approximately equal to an
expected return-to-port time previously designated by the operator
and stored in an expected return-to-port time storage section
(e.g., stored in one of the storage devices associated with the ECU
61). For example, the watercraft operator may have informed
friends, relatives or other potentially concerned persons that the
operator would return from a boating excursion by a certain time.
Alternatively, the watercraft operator may not be allowed to enter
the home port after a designated closing time.
[0082] The two return-to-port warnings are generated automatically
by the ECU 61, thereby freeing the operator and others aboard the
watercraft to concentrate on other matters (e.g., fishing,
recreational activities or other activities). Specifically, the ECU
61 reminds the operator of the need to return to the home port when
the operator has failed to monitor the amount of fuel remaining or
to monitor the time required for returning to the home port.
[0083] In particular embodiments, in addition to visually
displaying the return-to-port warning on the indication device 41,
additional devices are advantageously used to warn the operator.
For example, a speaker or siren may be used to produce an audible
sound, or a light emitting device may be used to produce a readily
observable visual effect.
[0084] The first return-to-port judgement section generates a
return-to-port distance warning to notify the operator that if the
watercraft travels further away from the home port, sufficient fuel
may not be available to enable the watercraft to return to the home
port under existing conditions. In particularly preferred
embodiments, the return-to-port distance warning is issued when the
following condition is met:
L<L0.times.k1, (6)
[0085] where L is the maximum cruising distance calculated above
using the equation (4), where L0 is the distance from the current
watercraft location to the home port (e.g., the return-to-port
distance in nautical miles), and where k1 is a safety factor having
a preferred value between approximately 1.2 and 1.3. In particular,
the return-to-port distance L0 is the straight line distance
calculated based on the differences between the coordinates of the
home port and the current coordinates of the watercraft 10, as
indicated by the GPS 42. The safety factor k1 accounts for possible
errors in the calculation of the maximum cruising distance L.
[0086] The second return-to-port judgement section generates a
return-to-port time warning to notify the operator that if the
watercraft travels further away from the home port, a danger exists
of arriving later than an expected return-to-port time designated
by the operator. For example, if the home port closed at a certain
time, the watercraft would not be able to enter if the watercraft
arrives after that certain time. The decision by the ECU 61 to
issue a return-to-port time warning is determined by comparing an
expected return-to-port time t2 to an estimated arrival time t1.
The return-to-port time warning is issued when the following
condition is met:
t2-t0<(t1-t0).times.k2=(L0/S).times.k2, (7)
[0087] where t0 is the current time and k2 is a safety factor
having a preferred value between approximately 1.2 and 1.3. In
certain embodiments, the quantity (t1-t0) is estimated as the
return-to-port distance L0 divided by the current velocity S of the
watercraft 10. In other embodiments, the quantity (t1-t0) is
estimated as the return-to-port distance L0 divided by a different
velocity such as some percentage of an estimated maximum velocity
attainable by the watercraft 10. The safety factor k2 accounts for
possible errors in the calculation of the velocity S, errors in the
calculation of the return-to-port distance L0, or errors in the
calculations of both values.
[0088] In particular embodiments, as illustrated, for example, by
the flowchart in FIG. 3, a procedure 100 is advantageously used by
the ECU 61 to determine when to issue one or more return-to-port
warnings. The procedure 100 is illustrative and should not be
construed as limiting because similar procedures consistent with
embodiments of the current invention may also be advantageously
used to determine when to issue a return-to-port warning based
either on the criteria described above or based on other criteria
such as a specific event, a condition of the watercraft 10, or a
particular weather condition.
[0089] The procedure 100 comprises a step 101 in which the location
(e.g., the coordinates) of the home port is set. The coordinates of
the home port are entered into the ECU 61 and are stored in the
storage device, in the auxiliary storage device, or in a similar
that is part of the ECU 61. In particular embodiments, the
coordinates of the home port are entered into the ECU 61 by the
operator. In alternative embodiments, the operator enters
appropriate information to identify the home port, such as, for
example, a name of the home port. Preferably, when the name of the
home port or other information identifying the home port is
entered, the coordinates of the home port are advantageously
determined from a correlation table stored in the auxiliary storage
device of the ECU 61.
[0090] The procedure 100 further comprises a step 102 in which the
expected or required return-to-port time t2 is entered when the
user has a specified time for arriving at the home port.
[0091] The procedure 100 further comprises a step 103 in which a
maximum cruising distance L is calculated. Preferably, the maximum
cruising distance L is calculated based on the amount of remaining
fuel .DELTA.V in the fuel tank 53 and the fuel consumption ratio E
calculated using the equation (4). Preferably, the amount of
remaining fuel .DELTA.V is calculated by time-integration of the
fuel flow rate based on an output of the fuel flow detector 52. In
other embodiments, the amount of remaining fuel .DELTA.V in the
fuel 53 is determined based on an output of the fuel level detector
51. In certain embodiments, the fuel consumption ratio E is
calculated based on the rate of fuel consumption F and the velocity
S of the watercraft 10.
[0092] The procedure 100 further comprises a step 104 in which a
return-to-port distance LO is calculated based on the difference
between the coordinates of the home port and the current
coordinates of the watercraft 10, as indicated by the GPS 42.
[0093] The procedure 100 further comprises a decision step 105 in
which the procedure determines whether the maximum cruising
distance L is sufficiently larger than the return-to-port distance
L0 based on the relationship in the condition (6).
[0094] If the relationship in the condition (6) is not true when
evaluated in the decision step 105, the procedure advances to a
step 106. If the relationship in the condition (6) is true, the
procedure advances to a decision step 107.
[0095] In the step 106, the ECU 61 issues a return-to-port distance
warning to indicate to the operator that the return-to-port
distance is approaching too close to the maximum cruising distance.
The return-to-port warning is indicated by the indication device
41, and, in alternative embodiments, the return-to-part warning is
also indicated by other warning devices. The procedure 100 then
returns to the step 103 to repeat the foregoing steps of the
procedure to again evaluate the conditions and determine whether a
return-to-port warning should be issued.
[0096] In the decision step 107, the procedure 100 determines
whether an expected return-to-port time t2 has been inputted and
stored in the ECU 61. If an expected return-to-port time t2 has not
been inputted and stored, the procedure returns to the step 103 to
again evaluate the conditions and determine whether a
return-to-port warning should be issued.
[0097] If an expected return-to-port time t2 has been inputted and
stored, the procedure advances from the decision step 107 to a step
108. In the step 108, an estimated arrival time t1 to the home port
is calculated. The estimated arrival time is derived by using the
return-to-port distance L0 divided by the current velocity S of the
watercraft 10 to determine the return-to-port travel time and
adding the return-to-port travel time to the current time t0.
[0098] After calculating the estimated arrival time t1 in the step
108, the procedure 100 advances to a step 109 and determines
whether the estimated arrival time t1 is sufficiently earlier than
the expected return-to-port time t2. It should be understood that
calculation of the estimated arrival time t1 in the step 108 and
the comparison of the estimated arrival time in the step 109
advantageously determine whether the relationship in the condition
(7) is satisfied.
[0099] If the procedure 100 determines in the step 109 that the
estimated arrival time t1 is not sufficiently earlier than the
expected return-to-port time t2, the procedure advances to a step
110 to issue a return-to-port time warning indicating that the
estimated arrival time t1 is approaching too close to the expected
return-to-port time t2. The return-to-port warning is indicated by
the indication device 41, and, in alternative embodiments, the
return-to-part warning is also indicated by other warning devices.
The procedure 100 then returns to the step 103 of the procedure to
again evaluate the conditions and determine whether a
return-to-port warning should be issued.
[0100] If the procedure 100 determines in the step 109 that the
estimated arrival time t1 is sufficiently earlier than the expected
return-to-port time t2, no warning is issued, and the procedure 100
returns to the step 103 of the procedure to again evaluate the
conditions and determine whether a return-to-port warning should be
issued.
[0101] Optimum Trim Position (Trim Angle)
[0102] As described above, the trim angle affects the fuel
efficiency of the watercraft 10. Preferably, an optimum trim angle
is indicated by the indication device 41 or other such device in
response to the velocity of the watercraft 10 and any other
relevant parameters to provide beneficial operational information
to the operator. The information enables the operator to set the
trim angle of the outboard motor 12 to correspond to the optimum
trim angle by operating the trim/tilt switch 23.
[0103] In particular embodiments, a conversion table is located in
the auxiliary storage device of the ECU 61. The conversion table
stores relationships between the optimum trim angle and the
velocity S, the load weight, and other relevant parameters. In such
embodiments, the value of an optimum trim angle is determined by
accessing the conversion table based on the values of the relevant
parameters. The values of some parameters used to access the
conversion table are measured or calculated by the ECU 61. Other
parameters, such as, for example, the load weight for the
watercraft 10 cannot be automatically measured in most watercraft;
however, such parameters may advantageously be entered manually by
the operator. The optimum trim angles for selected conditions can
be indicated, for example, using tables or graphs that represent a
relationship between the load weight and the corresponding optimum
trim angle.
[0104] Once all relevant parameters have been entered, the ECU 61
displays the optimum trim angle using the parameters to access the
value of the optimum trim angle in the conversion table. The
development of the values of the optimum trim angle responsive to
the changing velocity or the like can be found by a boat builder or
by a driver running the watercraft 10 under varying conditions of
the trim angle, velocity, and load weight, while measuring the fuel
consumption ratio E, stability and the like.
[0105] Other Conditions and Parameters of the Watercraft and the
Engine
[0106] In certain embodiments, the ECU 61 includes one or more
judgement sections that monitor other conditions of the watercraft
10 and the engine 62 of the outboard motor 12 and displays the
conditions on the indication device 41. For example the engine
speed measured by the engine speed sensor 74, may be displayed on
the indication device 41 along with a warning if the engine speed
reaches a limit that may cause damage (e.g., the engine is
operating in an abnormal speed region). Similarly, the measured
cooling water temperature is advantageously displayed along with
any indication that the temperature is outside an acceptable range
(e.g., the engine temperature is in an abnormal temperature
region).
[0107] In alternative embodiments, the ECU 61 monitors a plurality
of outboard motors 12 on a single watercraft 10, and information
regarding each outboard motor 12 is displayed on the single
indication device 41. If a problem develops with one or more of the
outboard motors 12, the occurrence of such events are reported by
the ECU 61 along with suggested points of inspection, suggested
methods of fixing the problem, and other information that is
relevant to the operator.
[0108] In alternative embodiments, points of inspection and methods
of fixing a problem are retrieved from information in a correlation
table stored in the auxiliary storage device of the ECU 61, and the
retrieved information is displayed on the display 41. In
particular, the ECU 61 advantageously uses the correlation table to
correlate abnormal parameters to points of inspection and to
methods of fixing a problem. For example, a rise in the cooling
water temperature resulting from blockage of the intake port for
cooling water could be correlated with a suggestion to check for
sea weed or other debris at the intake port. In other alternative
embodiments, the ECU 61 determines when parameters such as engine
speed and engine temperature are outside of a normal range and
reports such events to the operator using, for example, the
indication device 41 or some other suitable indication device such
as an audible alarm.
[0109] In certain embodiments, at least some of the information
received by the ECU 62 or derived using the ECU 62 is transmitted
to the indication device 41 in the form of graphical information or
another format readily interpreted by the operator. In other
embodiments additional devices are advantageously used to relay
information or issue warnings. For example, a speaker or siren may
be used to produce an audible sound, or a light emitting device may
be used to produce a readily observable visual effect.
[0110] The foregoing embodiments are exemplary and should not be
construed as limiting, since other embodiments consistent with the
present invention may be used by those skilled in the art for
particular sets of requirements. For example, a return-to-port
warning (return-to-port distance warning and return-to-port time
warning) can be set to have a plurality of stages such that the
warning changes form or magnitude as the amount of fuel remaining
in the fuel tank 53 continues to decrease. One advantageous method
to achieve the stages uses a plurality of numerical values for the
safety factors in the condition (6) and the condition (7).
[0111] The control signals applied to the input of the ECU 61 are
not limited to those produced by the start/stop switch 21, the
lever angle sensor 22, the trim/tilt switch 23 or the steering
sensor 31, but may advantageously include any other signals that
may represent conditions critical for the control of the outboard
motor 12. For example, if automatic operation of the watercraft 10
is possible based on the positional information from the GPS 42, a
signal from the GPS 42 may be indirectly utilized to control the
outboard motor 12. Thus, a signal indirectly utilized for the
control of the outboard motor 12 is included as a control
signal.
[0112] As described above, the preferred embodiments provide a
watercraft, an outboard motor and an outboard motor control device
that are capable of continuing the operation of the outboard motor
even if a portion of an inboard local area network develops an
abnormality. The preferred embodiments also provide a system that
includes an indication device capable of displaying warnings to an
operator when an abnormality has occurred. In addition to
abnormalities in the operation of the watercraft or the outboard
motor, the system also displays warnings based on the operating
conditions of the watercraft that may preclude the watercraft from
returning to a home port or other destination unless the operator
initiates navigational operations to direct the watercraft towards
the home port or other destination.
[0113] Although described above in connection with particular
embodiments of the present invention, it should be understood the
descriptions of the embodiments are illustrative of the invention
and are not intended to be limiting. Various modifications and
applications may occur to those skilled in the art without
departing from the true spirit and scope of the invention as
defined in the appended claims.
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